Zenith Pilot Big Date Flyback · Ref. 03.4000.3652/51.I003 · 20mm lug · 44mm case
At a Glance
| # | Best For | Strap | Material | Thickness |
|---|---|---|---|---|
| 1 | Overall / First Purchase | Tinware Grey Epsom Slim Strap | Epsom Calfskin | 2.2mm |
| 2 | Dressy / Formal | Matte Red Alligator Signature Strap | Alligator | 4.5–2.2mm |
| 3 | Everyday / Casual | Nubuck Black Ostrich Leg Signature Strap | Nubuck Calfskin | 4.5–2.2mm |
| 4 | Minimalist / Refined | Cognac Shell Cordovan Slim Strap | Shell Cordovan | 2.2mm |
| 5 | Casual / Relaxed | Black Baranil Signature Strap | Baranil Calfskin | 4.5–2.2mm |
| 6 | Active / Sporty | Navy Tropical CTS Rubber Strap | FKM Rubber (Tropical) | 4.0–3.3mm |
| 7 | Comfort / Wildcard | Serpentine Ostrich Leg Signature Strap | Ostrich | 4.5–2.2mm |
I have always believed that the right strap can fundamentally change how you experience a watch. The Zenith Pilot Big Date Flyback (ref. 03.4000.3652/51.I003) proves this better than most. The finishing and attention to detail speak for themselves. The 20mm lug width opens up a wide range of possibilities.
The case measures 44mm with a thickness of — proportions that sit comfortably on most wrists without dominating them. It strikes that balance between presence and wearability that makes it suited to almost any strap.
Here are my 7 picks — and why each one works.
Quick Specs
| Case diameter | 44mm |
| Lug width | 20mm |
| Lug-to-lug | |
| Case thickness | |
| Water resistance | 300m |
| Crystal | Sapphire with AR coating on caseback |
| Case material | Stainless steel and 18k Sedna gold |
| Movement | Calibre 9900, Co-Axial Master Chronometer chronograph, automatic, 60h power reserve |
The 20mm lug width means your options are curated but well-covered. Already know what you're looking for? Browse all Zenith Pilot Big Date Flyback-compatible straps on the Strap Finder →
1. Best Overall — Tinware Grey Epsom Slim Strap
Every watch needs a go-to strap, and for the Zenith Pilot Big Date Flyback, this is it.
The Tinware Grey Epsom Slim Strap features Epsom leather, tanned by Haas. The fine, uniform grain gives it a clean, contemporary look that resists scratches and moisture with ease. This is leather that looks as sharp six months from now as it does on day one. At 2.2mm thick, it balances presence and wearability nicely.
Paired with the Zenith Pilot Big Date Flyback's distinctive dial, this strap adds a layer of personality that the factory option does not offer. The case thickness means a padded strap like this one feels proportional and substantial.
A combination that's greater than the sum of its parts.
Worth a look in other colourways:
- Black Epsom Slim Strap
- Hunter Green Epsom Slim Strap
- Izmir Blue Epsom Slim Strap
- Orange Epsom Slim Strap
2. Best Dressy — Matte Red Alligator Signature Strap
When you need to dress the Zenith Pilot Big Date Flyback up, this is the strap that delivers.
The Matte Red Alligator Signature Strap is crafted from genuine alligator leather — not embossed calfskin, the real thing. Each scale pattern is unique, and the matte finish gives it a refined presence that catches light without being flashy. The leather is supple from the start with minimal break-in needed. At 4.5–2.2mm thick, it balances presence and wearability nicely.
On the Zenith Pilot Big Date Flyback, this strap preserves the watch's go-anywhere character. The 44mm case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
The range goes deeper if you want to explore:
- Matte Black Alligator Signature Strap
- Matte Navy Alligator Signature Strap
- Matte Himalayan Alligator Signature Strap
- Matte Mahogany Alligator Signature Strap
3. Best Everyday — Nubuck Black Ostrich Leg Signature Strap
An everyday strap needs to be comfortable from the jump and work with most of what you wear.
The Nubuck Black Ostrich Leg Signature Strap is crafted from nubuck leather — soft, velvety to the touch, and comfortable from the first wear. No break-in period needed. The suede-like texture adds a casual warmth that takes the edge off a formal watch without losing sophistication. At 4.5–2.2mm thick, it balances presence and wearability nicely.
On the Zenith Pilot Big Date Flyback, this strap preserves the watch's go-anywhere character. The 44mm case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
A combination that's greater than the sum of its parts.
4. Best Minimalist — Cognac Shell Cordovan Slim Strap
Sometimes less is more. This strap proves it.
The Cognac Shell Cordovan Slim Strap is crafted from premium materials with careful attention to detail and construction quality. At 2.2mm thick, it balances presence and wearability nicely.
On the Zenith Pilot Big Date Flyback, this strap preserves the watch's go-anywhere character. The 44mm case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
A combination that's greater than the sum of its parts.
Worth a look in other colourways:
- Black Shell Cordovan Slim Strap
- Navy Shell Cordovan Slim Strap
- Natural Shell Cordovan Slim Strap
- Green Shell Cordovan Slim Strap
5. Best Casual — Black Baranil Signature Strap
Casual doesn't mean careless — this strap adds character without trying too hard.
The Black Baranil Signature Strap is crafted from premium materials with careful attention to detail and construction quality. At 4.5–2.2mm thick, it balances presence and wearability nicely.
Paired with the Zenith Pilot Big Date Flyback's distinctive dial, this strap adds a layer of personality that the factory option does not offer. The case thickness means a padded strap like this one feels proportional and substantial.
The kind of strap that earns a permanent spot in your rotation.
If this style appeals but you want a different tone:
- Fauve Baranil Signature Strap
- Cobalt Baranil Signature Strap
- Cream Baranil Signature Strap
- Gold Baranil Signature Strap
6. Best Sporty — Navy Tropical CTS Rubber Strap
Casual energy with a sportier edge. This strap shifts the mood without going full tool-watch.
The Navy Tropical CTS Rubber Strap is made from FKM rubber — a high-performance elastomer that resists chemicals, heat, and ageing. Unlike silicone, it does not attract dust or lint. Cut-to-size construction means you trim it to your exact wrist measurement — no leftover tail, no keepers. At 4.0–3.3mm thick, it balances presence and wearability nicely.
The Zenith Pilot Big Date Flyback's 44mm case is ideally proportioned for this strap. Whether you are wearing it casually or dressing it up, the combination feels intentional. It is the kind of pairing where both the watch and strap look better together than apart.
The range goes deeper if you want to explore:
7. The Wildcard — Serpentine Ostrich Leg Signature Strap
This one's different — and that's exactly the point.
The Serpentine Ostrich Leg Signature Strap is made from ostrich leg leather. Unlike the body leather, ostrich leg has a distinctive scale-like texture with natural ridges and patterns that give it an almost reptilian character. It is soft, supple, and needs virtually no break-in time. At 4.5–2.2mm thick, it balances presence and wearability nicely.
On the Zenith Pilot Big Date Flyback, this strap preserves the watch's go-anywhere character. The 44mm case at thick pairs naturally with the padded construction without creating any imbalance on the wrist.
It's the kind of pairing that makes you wonder why you didn't try it sooner.
Other colours worth considering:
- Blue Jean Ostrich Leg Signature Strap
- Tapestry Grey Ostrich Leg Signature Strap
- Copper Ostrich Leg Signature Strap
- Dark Grey Ostrich Leg Signature Strap
A Note on Buckle Colour
Quick but important: always match your buckle to your case. The Zenith Pilot Big Date Flyback's Stainless steel and 18k Sedna gold case calls for a gold buckle to match. All Delugs leather straps ship with a pin buckle and can be upgraded to a Spring Deployant Clasp for extra security and convenience. All Delugs straps come with quick-release spring bars pre-installed, so swapping straps takes seconds.
How to Change the Strap on Your Zenith Pilot Big Date Flyback
Swapping straps on the Zenith Pilot Big Date Flyback is one of the easiest upgrades you can make — and with Delugs straps, you don't even need a tool.
If your Zenith Pilot Big Date Flyback came on a bracelet, you'll first need to remove it. The easiest way to do this at home is with a Bracelet Removal Tool, which lets you compress the spring bars without risking scratches to the lugs or caseback. Once the bracelet is off, you can slide your new Delugs strap straight in.
All Delugs straps come with quick-release spring bars already pre-installed, so changing straps is completely tool-free. Here's how:
- Prepare your workspace. Lay the watch face-down on a soft cloth or microfiber pad to protect the caseback from scratches.
- Release the spring bar. Locate the small lever on the quick-release spring bar. Pull it back with your fingernail or fingertip to compress the bar.
- Remove the strap. While holding the lever, angle the strap out from between the lugs. Repeat for the other side.
- Insert the new strap. Slide one end of the spring bar into the lug hole. Pull the lever on the quick-release spring bar knob, guide the entire spring bar into the opposite lug hole, and then release the knob. You should hear a small click when the spring bar extends and seats into the lug hole.
- Check the fit. Give the strap a gentle tug to make sure both spring bars are securely locked in. If there's any play, reseat the spring bar.
The entire process takes under a minute once you get the hang of it — no spring bar tool required. The Zenith Pilot Big Date Flyback uses a standard 20mm lug width, and all Delugs straps in 20mm will fit perfectly.
Frequently Asked Questions
What is the lug width of the Zenith 03.4000.3652/51.I003?
The Zenith 03.4000.3652/51.I003 has a 20mm lug width. While 20mm is less common than 20mm, there is still a strong selection of quality straps available. All Delugs straps are available in 20mm.
What is the reference number for the Zenith Pilot Big Date Flyback?
The reference number for the Zenith Pilot Big Date Flyback is 03.4000.3652/51.I003. You can find this on the caseback of your watch or on the original paperwork. Knowing your reference number helps ensure you get the right lug width when ordering a strap.
Can I use a dressy leather strap on a Zenith versatile watch?
The Pilot Big Date Flyback is one of the most versatile watches in the Zenith lineup — it takes both dressy and casual straps equally well. That's part of what makes it such a rewarding watch for strap changes. Don't be afraid to experiment.
Do Delugs straps come with spring bars?
Yes — every Delugs strap comes with quick-release spring bars pre-installed. This means you can change straps by hand in seconds, without needing any tools. The quick-release mechanism uses a small lever that you pull with your fingertip to compress the spring bar.
What is the best strap material for the Zenith Pilot Big Date Flyback?
The Pilot Big Date Flyback's versatile nature means it works with almost everything. Start with what matches your most common wearing occasion — rubber or sailcloth for active use, nubuck or waxy leather for everyday, and alligator or saffiano for dressier moments. The Strap Finder makes it easy to browse by material and style.
Does Zenith use quick-release spring bars?
Most Zenith watches use standard spring bars that require a tool to remove. All Delugs straps come with quick-release spring bars pre-installed, so once you make the switch, future changes are completely tool-free.
Where can I find straps compatible with the Zenith 03.4000.3652/51.I003?
The Zenith Strap Finder shows every Delugs strap compatible with the 03.4000.3652/51.I003, filtered by lug width and style. You can also use the general Strap Finder to browse by brand, collection, and material. If you need help choosing, our team is available 24/7 via live chat.
Finding Your Strap
The beauty of the Zenith Pilot Big Date Flyback is that it rewards experimentation. A dressy alligator for the office, nubuck for the weekend — each strap brings out a different side of the watch.
Use the Zenith Pilot Big Date Flyback Strap Finder to see every compatible strap in one place, filtered to your exact reference. Or if you'd rather explore by feel, the general Zenith Strap Finder lets you browse the full lineup and find your match.
Not sure which strap is right for your specific Pilot Big Date Flyback? Our team is available 24/7 via live chat — drop us a message and we'll help you find the perfect match for your watch, wrist size, and style.
About Delugs
Founded in 2018 and headquartered in Singapore, Delugs is dedicated to elevating the experience of watch ownership through the simple yet powerful act of strap changing. We believe that straps are integral to how a timepiece is worn, perceived, and enjoyed. Our mission is to make strap changing a lifestyle — an everyday act of self-expression and versatility.
Delugs is an independent brand with a global community of clients, with a strong online presence and growing physical retail footprint. Our direct-to-consumer focus keeps us closely connected with the watch enthusiast community — fostering conversations, hosting events, and helping shape a more inclusive and expressive culture around watch collecting. We also work closely with watch brands to craft straps that complement their timepieces, bridging the gap between brand and collector, form and function.
Our catalogue spans leather, rubber, and fabric straps, with options for every watch and every occasion. We are committed to craftsmanship and quality, product design and innovation, and outstanding customer service. We offer watch owners the freedom to change straps as easily as changing outfits, and the opportunity to engage more deeply with the watches they love.
Visit our flagship boutique at Raffles Hotel, Singapore →
— Marcus
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